• Recurrent uncontrolled passage of fecal material for ≥3 months
• Two or more episodes of uncontrolled passage required (changed from "recurrent")
• Fecal staining of underwear included; flatus incontinence excluded
• At least one FI episode per month on 4-week stool diary required for clinical purposes

• Frequency: Term "recurrent" was nonspecific; 55% had <1 FI episode/month, yet even infrequent FI impairs QOL
• Duration: Increased from 3 to 6 months due to lifestyle changes and alignment with Rome criteria
• Research: Up to 50% have <1 FI episode/week with significant QOL impairment; threshold of 1/week may decrease study eligibility

• Pooled global prevalence: 8.0% (all studies), 5.4% (Rome criteria)
• Higher in older persons (9.3%) vs younger (4.9%)
• Higher in women (9.1%) than men (7.4%)

• FI significantly impairs QOL → restricts social activities, concerns about hygiene/odor/coping/fear/self-esteem/embarrassment/sexual relationships
• Anxiety and depression associated with more severe FI symptoms and QOL impairment
• More overlapping DGBI → worse outcomes
• FI mixed with constipation → lower QOL than isolated FI

• Demographics: Age, female sex
• Obstetric trauma: OASI during vaginal/instrument-assisted delivery → leading cause of sphincter trauma
• Other: Diarrhea, cholecystectomy, diabetes, neurological/inflammatory diseases
• Age-related: Muscle decline + emerging risk factors explain FI decades after vaginal delivery
• Contributory: Smoking (EAS atrophy), obesity, structural disorders (rectocele, rectal intussusception)
• Surgical: Anorectal surgery for hemorrhoids/fissures/fistula/cancer can damage sphincters
• Other causes: Proctitis, fecal impaction with overflow diarrhea (impairs compliance)

• Continence mechanisms: IAS and EAS function, puborectalis, anorectal neurophysiology (pudendal/levator ani nerves, inferior hypogastric plexus, pelvic splanchnic nerves), recto-anal sensation, rectal compliance
• IAS dysfunction: Decreased resting pressure from sphincter defects/thinning/neurological injury; common in idiopathic FI and scleroderma
• EAS damage: Neuropathy, myopathy, decreased cortico-spinal input → reduced squeeze pressure
• Levator ani: Contributes via flap-valve effect; anal cushions + sphincter tone provide closure
• Perineal descent: Excessive → obtuse anorectal angle → impairs flap valve mechanism

• Up to 1/3 of FI patients have normal sphincter pressures; many have concurrent constipation or pelvic organ prolapse
• Rectal hyposensitivity → reduced urge sensation, fecal retention, leakage before EAS contraction
• Rectal hypersensitivity + reduced compliance → urgency
• Rectal capacity reduced in women with FI → associated with urgency

• Anal sphincter relaxation during rectal distention allows sampling to discriminate gas/liquid/stool
• FI patients exhibit fewer sampling responses and reduced anal sensation → deprived of sensory feedback
• Impaired rectosigmoid brake may predispose to FI

• FI can occur during periods of stress
• Anxiety and depression common; concurrent DGBI worsens severity and psychological distress → gut-brain axis dysfunction contributes

• Patients may not volunteer FI → ask directly
• Bowel questionnaires useful but limited by recall bias
• Prospective stool diaries or digital apps with pictorial scales improve accuracy
• Assess: predisposing conditions, FI severity (type: solid/liquid/gas, quantity, frequency), awareness of urge prior to incontinence
• Definitions: Staining = leakage 1-2 tablespoons; Soiling = more extensive leakage
• Assess timing: after meals, BMs, exercise, or night → provides etiologic clues

• Solid stool incontinence → more severe sphincter weakness than liquid alone
• Nocturnal incontinence → uncommon, often reflects IAS dysfunction (diabetes, scleroderma)
• Urge incontinence: Strong desire to defecate prior to leakage → associated with reduced squeeze pressure/duration, reduced rectal capacity, rectal hypersensitivity
• Passive incontinence: Without awareness → often associated with lower resting pressure

• Abdominal and neurological examination + meticulous DRE required

• Pudendal Nerve Terminal Motor Latency (PNTML): Measures latency after intrarectal stimulation; prolonged = neuropathy; infrequently performed due to methodological limitations
• Electromyography (EMG): Surface, needle, single-fiber methodologies; findings: normal, neurogenic, muscle injury, nonspecific
• Sensory Testing: Anal sensation tested via electrical/thermal stimulation (unclear utility); rectal sensation evaluated by balloon distension during ARM or barostat
• Translumbosacral Anorectal Magnetic Stimulation (TAMS): Novel test measuring MEP latencies after magnetic stimulation of lumbar/sacral plexus; superior to PNTML; 50% show lumbar and sacral plexus neuropathy; afferent cortico-anorectal evoked potentials prolonged in FI

• Goal: Optimize stool form, restore normal bowel habit (especially with loose stools)
• Dietary trials: Low lactose or low FODMAP diet, psyllium (not gum arabic/carboxymethylcellulose) → improved FI vs placebo
• Antidiarrheals: Loperamide/diphenoxylate-atropine improve stool consistency; loperamide also increases IAS tone
• Amitriptyline: May improve FI via anticholinergic effects
• Bile acid sequestration: Cholestyramine benefits diarrhea + FI
• Clonidine: RCT showed improvement in stool form, decreased FI episodes when combined with colesevelam (not placebo alone)

• Suppositories (glycerine, bisacodyl), low volume enemas (water/osmotic), irrigation → useful in patients with abnormal evacuation
• Elderly regimen: Lactulose 10 mL BID + weekly enemas improved FI
• Transanal irrigation (low/high volume): RCTs support efficacy in neurogenic bowel, spina bifida, anterior resection syndrome; improved FI severity, constipation, bowel satisfaction; >1/3 discontinued within year due to poor satisfaction/side effects
• Anal plug devices: One pivotal study: 77% of 73 completers, 62% of 91 ITT participants achieved ≥50% reduction in FI frequency
• Vaginal bowel control device (FDA-approved): Inflatable balloon compresses rectum; 65/110 women successfully fitted, 79% achieved ≥50% reduction at 1 month
• Anal insert device (FDA-approved): Safe, well-tolerated; >75% and 54% reported 50% and 75% reduction in moderate/full BM FI

• Uses operant conditioning/instrumental learning + Kegel exercises
• Teaches patients to selectively contract EAS and puborectalis → improve strength/duration of anal squeeze, correct dyssynergia
• Feedback via visual tracings of balloon volume and/or anorectal pressure
• Reinforced by therapist + sensory perception with progressively smaller

• Consider for patients unresponsive to optimal medical and behavioral therapy
• Available options range from minimally invasive neuromodulation to reconstructive approaches
• High quality evidence of long-term efficacy is limited

• Historically, most surgery directed toward repair of anal sphincter defects
• Overlapping anterior sphincteroplasty: Up to 60–85% improved in short-term studies
• Long-term results disappointing: Failure rates of ~50% after 40–60 months
• Recent innovations: Autologous skeletal muscle derived cell implantation, bioengineered IAS from autologous cells

• Colostomy remains last resort for severe FI
• Improves QOL

• Three anorectal pain syndromes described: Levator ani syndrome (LAS), unexplained anorectal pain, proctalgia fugax
• Distinguished based on pain duration and presence/absence of levator ani tenderness during DRE

• LAS: Vague, dull ache or pressure sensation in rectum; worse with sitting than standing/lying
• DRE reveals tenderness on palpation of levator ani muscles
• Recent study: DRE reproduced pain in one or more anal quadrants with similar pain severity (not just left-sided)
• Unexplained anorectal pain: Same symptom criteria as LAS but no tenderness during traction on puborectalis

Must include all:

1. Chronic or recurrent anorectal pain

2. Episodes last 30 minutes or longer

3. Tenderness during traction on puborectalis

4. Exclusion of other causes: anal fissure, thrombosed hemorrhoids, malignancy, infectious/inflammatory causes (IBD, perianal abscess/fistula), prostatitis, coccygodynia, gynecological causes

• Symptom criteria for LAS but no tenderness during traction on puborectalis muscle

• Order of other conditions changed to be consistent with frequency
• "Structural alterations" replaced with "disorders"
• "Posterior traction" removed since traction at other quadrants also evokes pain
• Term "Functional" removed

• Prevalence of anorectal pain (all causes): 11.6% in community; similar across genders
• LAS prevalence: 1.1% (internet survey), 0.7% (household survey) in Rome Foundation Global Epidemiology Study

• Diagnosis relies on characteristic episodes of anorectal pain with levator muscle tenderness on palpation
• Exclude fissure; anoscopy/sigmoidoscopy may identify mucosal disease
• If perianal disease suspected (abscess/fistula): cross-sectional imaging
• Consider: anorectal manometry, defecography, TAMS test
• TAMS findings: Prolonged MEP latencies indicating lumbar/sacral plexus neuropathy; weak anal sphincters, features of DD with prolonged balloon expulsion time

• RCT findings: 87% of patients with levator tenderness reported adequate pain relief after BT vs 45% after electrical stimulation vs 22% after massage
• Patients without tenderness did not benefit from any therapy
• Electrogalvanic stimulation considered if BT unavailable
• Retrospective studies suggested improvement after intra-anal or intra-levator botulinum A toxin injection; one RCT found no benefit over placebo
• Open label study of TNT: significant improvement in anorectal pain and lumbosacral neuropathy
• Ineffective: muscle relaxants, diazepam, SNS, sitz baths, radiofrequency, pudendal infiltration, transgluteal decompression, TENS, laparoscopic decompression

• Sudden, severe pain in rectal area lasting seconds to minutes, then disappearing completely
• Attacks infrequent: typically <5 times/year in 51% of patients
• Pain described as cramping, gnawing, aching, or stabbing; ranges from uncomfortable to unbearable
• Can happen anytime; 50% report nocturnal attacks interrupting activities

Must include all:

1. Recurrent episodes of pain localized to anorectum, unrelated to defecation

2. Episodes last from seconds to minutes

3. No anorectal pain between episodes

4. Exclusion of other causes: anal fissure, thrombosed hemorrhoids, malignancy, infectious/inflammatory causes (IBD, perianal abscess/fistula), prostatitis, coccygodynia, major structural disorders of pelvic floor

• Prevalence: 5.6% (internet survey), 1.5% (household survey)
• Questionnaire-based → other anorectal disorders not excluded
• 1.3-fold more common in women; occurs in children
• Few patients seek healthcare, but can be disabling

• Diagnosis based on characteristic symptoms and exclusion of anorectal and pelvic pathophysiology
• Chronic pelvic pain pathologies (endometriosis in women, chronic prostatitis in men) may mimic symptoms

• Described as "harmless, unpleasant, and incurable"
• Reassurance often sufficient; frequent/severe attacks may require therapy
• RCT: Inhaled salbutamol shortened duration of severe and prolonged attacks vs placebo
• Other options suggested (no comparative studies): clonidine, amylnitrite, nitroglycerine, neuromodulators, behavioral therapies

• Characterized by paradoxical contraction or inadequate relaxation of pelvic floor muscles and/or inadequate propulsive forces during attempted defecation
• Symptoms alone do not distinguish DD from other evacuation disorders; some asymptomatic controls show dyssynergia pattern
• Diagnosis requires constipation symptoms + abnormal anorectal tests
• Term "DD" preferred over "pelvic floor dyssynergia" since most DD patients report only difficult defecation, not urinary or sexual dysfunction

• Population prevalence uncertain (requires physiologic testing)
• Of 11,112 constipated patients in community: 516 had undergone anal manometry; 245 (47%) had DD (209 women, 36 men)
• Age-adjusted incidence per 100,000 person-years: 31.8 [95% CI, 27.4–36.1] in women vs 6.6 [95% CI, 4.4–8.9] in men (p<0.0001)
• Before diagnosis: ~30% had IBS, 48% had psychiatric diagnosis, 18% had abuse history, 21% reported urinary and/or fecal incontinence
• At tertiary centers: DD prevalence among constipated patients ranges 20% to 81%

Must include all:

1. One or more symptoms of difficult evacuation (excessive straining, digital maneuvers to evacuate, sensation of anorectal blockage, feeling of incomplete evacuation) with at least 25% of BMs; may satisfy criteria for chronic constipation or IBS

2. During attempted defecation, impaired evacuation demonstrated by any one of:

• Reduced rectoanal pressure gradient or abnormal anorectal evacuation pattern on ARM
• Abnormal balloon expulsion test (BET)
• Impaired rectal evacuation with defecography

• Term "functional" removed
• "Defecation disorders" is broad (includes functional and structural like rectal prolapse); DD more specific
• Removal of Type 3 dyssynergia and EMG (latter rarely used clinically)
• Symptom criteria: Many constipated patients report difficult evacuation but don't satisfy Rome IV functional constipation or IBS; Rome V allows diagnosis if ≥1 symptom occurs >25% of time and physiology criteria fulfilled
• Rome IV required abnormalities in ≥2 of 3 modalities (balloon expulsion, manometry, imaging) but concordance limited
• Rome V proposal: Any one abnormal finding sufficient to diagnose DD in patients with difficult evacuation (prolonged BET, reduced gradient, abnormal pattern, or reduced rectal evacuation by defecography)
• Rationale: Abnormal BET and gradient are 81% and 86% specific, respectively, for predicting reduced rectal evacuation; avoids unnecessary tests with radiation exposure
• Classification: Patients with one abnormal test = probable DD; ≥2 abnormal tests = definite DD
• Rectoanal Gradient (RAG): Best manometry measure of abnormal evacuation; reduced gradient reflects inadequate rectal propulsive force and/or impaired anal relaxation
• Subclassification removed: Inadequate propulsion and paradoxical contraction subtypes don't reliably discriminate healthy from DD patients or predict BT response

• Patient attempts to expel water-filled rectal balloon (50 ml or inflated until defecatory desire) in privacy, seated on commode
• Normal expulsion times: 20 seconds to 2 minutes; 1-minute cutoff recommended
• Results highly reproducible (90% of individuals across days)
• Useful as screening test; doesn't reveal DD pathophysiology
• May be normal in some patients with constipation and features of DD by defecography or manometry

• Intra-rectal and anal pressures measured during attempted defecation
• Earlier studies used water-perfused or solid-state manometry catheters; newer options include HR-ARM (interpolates pressures between multiple circumferential sensors) and air-charged, disposable catheters
• Normal pattern: Increased intrarectal pressure associated with anal relaxation